Perfluoroelastomers have long been used in a variety of applications that require excellent resistance to high temperatures, oxidative and chemical attack. One particularly outstanding fluoropolymer that has been used in elastomeric applications is that prepared from tetrafluoroethylene (TFE) and perfluoro (methyl vinyl) ether (PMVE). To permit the crosslinking in these copolymers that is essential to good elastomeric properties, a small percentage of termonomer is incorporated, as described, for example, in Finlay, U.S. Pat. No. 4,529,784, Apotheker et al., U.S. Pat. No. 4,035,565, and Breazeale, U.S. Pat. No. 4,281,092.
In the past, such perfluoroelastomers have been cured by compounding with the dipotassium salt of bis-phenol AF (K.sub.2 AF) or peroxide curing agents, followed by treatment with elevated heat and/or pressure to cure the polymer. While these techniques have produced excellent cured products, it would be desireable to have a similar cured product without the presence of the curing agent residues, which can exude during subsequent processing or use. Fluoropolymers have, in the past, been treated with ionizing radiation to promote curing, as described, for example in U.S. Pat. Nos. 3,223,689, 3,513,043, 4,256,856, and 4,565,614. However, such techniques have previously been limited to those compositions which were not perfluorinated. It was previously concluded that radiation would tend to degrade a perfluoropolymer without effective curing.